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2004 Progress Report: Pesticide Exposure Assessment Project
EPA Grant Number: R831710C002Subproject: this is subproject number 002 , established and managed by the Center Director under grant R831710
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: University of California Berkeley Center for Children’s Environmental Health Research
Center Director: Eskenazi, Brenda
Title: Pesticide Exposure Assessment Project
Investigators: McKone, Thomas
Institution: University of California - Berkeley
EPA Project Officer: Fields, Nigel
Project Period: May 1, 2004 through October 31, 2008
Project Period Covered by this Report: May 1, 2004 through October 31, 2005
Project Amount: Refer to main center abstract for funding details.
RFA: Centers for Children's Environmental Health and Disease Prevention Research (2003)
Research Category: Children's Health , Health Effects
Description:
Objective:The objectives of this research project are to:
- Evaluate changes in maternal organophosphate (OP) pesticide tissue distributions immediately before and after birth. We will enroll 30 women who are planning a Cesarean delivery and collect urine, saliva, and blood immediately before and after delivery, as well as maternal and cord blood at delivery and colostrum/breast milk after birth. We will measure OP pesticides and/or metabolites in these samples and use this information to modify existing pregnancy physiologically based pharmacokinetic (PBPK) models to describe OP pesticide tissue distributions immediately before and after birth.
- Determine the best and most convenient matrix for assessing exposure to organophosphate pesticides in children. We will collect 24-hour, first morning void, and random spot urine and saliva samples from 25 children ages 4-6 years and will measure OP pesticide metabolites in urine and saliva samples. We will determine whether OP pesticide metabolite levels in spot or first-morning void samples represent OP pesticide levels in 24-hour urine samples, considered the “gold standard.” We also will determine whether urinary OP pesticide metabolite levels are correlated with total OP pesticides measured in saliva. Through this validation study we will identify the most appropriate exposure biomarker(s) to be analyzed for the Center for Health Assessment of Mothers and Children of Salinas (CHAMACOS) cohort’s 60-month assessment.
- Quantify the relative contribution of diet to children’s OP pesticide exposures in agricultural and urban communities. We will conduct a randomized two-phase crossover trial of organic produce among 20 children living in an urban community (Oakland) and 20 children living in an agricultural community (Salinas) in California. W will determine if: (1) children with organic diets have lower OP pesticide metabolite levels; (2) children living in the Oakland area have lower pesticide exposures compared to Salinas; and (3) the proportion of exposure attributable to diet is different in each community.
- Characterize urinary OP pesticide metabolite levels in preschool and school-aged children and identify correlates of exposure. We will measure urinary OP pesticide metabolite levels in children from the CHAMACOS cohort study at ages 42 and 60 months and determine how these levels vary by gender and age and what factors predict these exposures, including season of urine collection, home or nearby agricultural pesticide use, and occupation of household members. We also will incorporate data collected at ages 6, 12, and 24 months to create a longitudinal dataset that will enable us to evaluate age and other variables as predictors and effect modifiers of total OP pesticide metabolites in urine over time. We will investigate whether the relative contribution of each source of exposure varies as children age.
Overview
The following progress has been made in our exposure project:
We conducted field work for Child Validation Study (CVS) addressing Objective 2. Activities included obtaining Institutional Review Board (IRB) approval, developing questionnaire and home inspection instruments, developing biological sample collection and processing protocols, training field staff, recruiting participants, collecting samples, and shipping samples to the Centers for Disease Control and Prevention (CDC). We enrolled 25 children ages 4-6 years as planned and collected 7 consecutive daily spot urine samples. On 2 of the 7 days, we also collected all child urine, which will enable us to compare exposure estimates based on pesticide metabolite levels in spot and 24-hour urine samples. We also will be able to calculate intra- and interindividual variability in metabolite levels. We collected 50 saliva and 8 hair samples from the children. The samples were collected for experimental work that CDC is conducting to validate laboratory methods for this media. If the analysis of pesticides in saliva in successful, we will compare exposure estimates based on saliva measurements with urinary metabolite levels. CDC currently is analyzing the CVS urine samples and initial findings will be presented at International Society of Exposure Analysis (ISEA) in October 2004.
In support of Objective 1, the Peripartum Pesticide Excretion Study (PPES), we have scheduled a meeting for November 2004 with our PBPK model consultants, including Drs. Dale Hattis, John Young, and Gary Ginsberg. Field work for the PPES will be planned after the November meeting.
The study instruments (e.g., questionnaire, home walk-through form) for administration at the 42-month questionnaire, neurodevelopment assessment, and home visit have been developed, translated, piloted, and implemented:
- The 42-month questionnaire, asking about various health, behavior, and exposure variables, has been completed for 253 children.
- Urine samples to assess pesticide exposure have been collected from 229 participants.
- We also are collecting and storing saliva samples for future use if CDC is successful in their effort to analyze pesticides in this media. Saliva has been collected from 216 participating children.
- Home visits to assess pesticide, allergen, and other environmental exposures in the home have been conducted on 217 participants.
Dr. Asa Bradman participated on the Exposure to Chemical Agents Workgroup for the National Children’s Study. Ongoing Center Exposure Activities for the previous 5 years includes:
- Data entry of the 24-month home walkthrough and questionnaire is complete.
- Laboratory data for pesticide urinary metabolites in 24-month-old children was provided by CDC in June 2004.
- Geographic information system (GIS) analysis of pesticide use reporting data and levels in house dust is nearly complete and will be presented at ISEA in 2004.
- Statistical analyses of the pesticide urinary metabolite data to address objectives for both the exposure and health studies are continuing.
- Data analysis of laboratory data for pesticide levels in environment samples for the Quantitative Exposure Assessment collaboration with the U.S. Environmental Protection Agency (EPA) was completed and a manuscript was written.
- Pesticide exposure models for pregnant women and children have been refined.
- Time activity data based on videotapes have been summarized and used as inputs for a dermal exposure model (Stanford group).
- Rosana Hernandez, a Ph.D. student, spent a second summer at CDC to work on a methods development project to measure non-persistent pesticides in breast milk. Gas chromatography/mass spectroscopy (GC/MS) and liquid chromatography/mass spectroscopy (LC/MS) methods were developed. This work will, in part, support Ms. Hernandez’s dissertation.
- A manuscript examining the relationship between pesticide use and air monitoring was submitted. This analysis helped develop methods to examine the relationship of pesticide use data and pesticide levels in urine and dust.
- Ray Chavira, EPA Region 9 and University of California–Los Angeles Ph.D. candidate, conducted data analysis and began writing up work on pesticides in vehicle dust.
Research Changes
For the child validation study, spot urine samples were collected over 7 consecutive days instead of 8. This change was made to better accommodate needs of participants and reduce overlap between participants, thereby reducing logistical complexities of the study.
Obstacles Encountered
Delays in funding resulted in some changes to our research plans and timing. We prioritized the cohort study. Therefore, we completed the CVS fieldwork as scheduled (see above). We also continued to follow the cohort. The peripartum excretion study will occur later than originally planned.
Significance
The current and planned research will address key research needs in assessing pesticide exposure to children and support implementation of the Food Quality Protection Act. The CVS addresses key questions about the utility of spot urine samples to estimate exposure and will help us identify the best biomarker to assess exposure. The findings from this study will apply directly to the planning process for the National Children’s Study, a longitudinal cohort study of 100,000 U.S. children. The ongoing cohort study will provide quantitative, longitudinal information on the relationship between nonoccupational exposure risk factors, home contamination, and children’s pesticide exposure. Finally, planned studies on pesticide excretion at birth will improve efforts to develop PBPK models describing pesticide kinetics and early childhood exposures (Objective 1) and the randomized two-phase crossover trial of organic produce will directly assess the contribution of children’s diet pesticide exposure. All of these studies will generate information needed for the Food Quality Protection Act.
Human Subjects
We have received approvals as needed from the human subjects committees at the University of California at Berkeley, CDC, California State Department of Health Services, University of California at Los Angeles, and Stanford for all planned or ongoing research. Appropriate assurances have also been obtained for collaborations with the Clinica de Salud del Valle Salinas and the Bioethics Committee of Natividad Medical Center. We obtained a separate IRB approval, #CPHS-2003-12-41, for the CVS study described above. This study involved the recruitment of 50 children from outside the main CHAMACOS cohort study.
Future Activities:We plan to accomplish the following:
- Complete 42-month neurobehavioral assessments and home visits and urine and salvia collections.
- Continue with data entry and integration of data sources (study instruments, CDC urine data, state Pesticide Use Reporting data, etc).
- Continue data analysis and manuscript preparation.
- Plan for 60 month neurobehavioral assessments, home visits, urine, and blood collections, which will begin in February 2005.
- After the November 2004 meeting with PBPK, model consultants will plan a field study to collect biological samples for the peripartum pesticide excretion study.
Journal Articles on this Report: 4 Displayed | Download in RIS Format
| Other subproject views: | All 15 publications | 4 publications in selected types | All 4 journal articles |
| Other center views: | All 114 publications | 67 publications in selected types | All 65 journal articles |
| Type | Citation | ||
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Bravo R, Caltabiano LM, Weerasekera G, Whitehead RD, Fernandez C, Needham LL, Bradman A, Barr DB. Measurement of dialkyl phosphate metabolites of organophosphorus pesticides in human urine using lyophilization with gas chromatography-tandem mass spectrometry and isotope dilution quantification. Journal of Exposure Analysis and Environmental Epidemiology 2004;14(3):249-259. |
R831710 (2004) R831710 (2005) R831710C002 (2004) |
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Castorina R, Woodruff TJ. Assessment of potential risk levels associated with U.S. Environmental Protection Agency reference values. Environmental Health Perspectives 2003;111(10):1318-1325. |
R831710 (2004) R831710 (2005) R831710C002 (2004) |
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Eskenazi B, Bradman A, Gladstone EA, Jaramillo S, Birch K, Holland N. CHAMACOS, a longitudinal birth cohort study: lessons from the fields. Journal of Children’s Health 2003;1(1):3-27. |
R831710 (2004) R831710 (2005) R831710C002 (2004) |
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Riley WJ, McKone TE, Cohen Hubal EA. Estimating contaminant dose for intermittent dermal contact: model development, testing and application. Risk Analysis 2004;24(1):73-85. |
R831710 (2004) R831710 (2005) R831710C002 (2004) |
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dialkyl phosphate, environmental management, health, pesticides, scientific discipline, children’s health, health risk assessment, pesticide types, risk assessment, human health risk assessment, agricultural community, airway disease, allergen, assessment of exposure, childhood respiratory disease, children's environmental health, community-based intervention, environmental health hazard, environmental risks, exposure assessment, health effects, insecticides, outreach and education, pesticide exposure,
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ENVIRONMENTAL MANAGEMENT, Scientific Discipline, Health, RFA, PESTICIDES, Risk Assessment, Health Risk Assessment, Children's Health, Pesticide Types, exposure assessment, insecticides, allergen, health effects, respiratory problems, children's environmental health, assessment of exposure, childhood respiratory disease, outreach and education, agricultural community, community-based intervention, pesticide exposure, airway disease, environmental risks, environmental health hazard
Relevant Websites:
http://ehs.sph.berkeley.edu/chamacos
Progress and Final Reports:
Original Abstract
2005 Progress Report
Main Center Abstract and Reports:
R831710 University of California Berkeley Center for Children’s Environmental Health Research
Subprojects under this Center:
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R831710C001 A Community-Based Participatory Research Project: CHAMACOS
R831710C002 Pesticide Exposure Assessment Project
R831710C003 Mechanisms of Pesticide Neuro and Immunotoxicity in Children Project
R831710C004 Community Outreach and Translation Core